Information and communication technology innovations (ICT) are considered to be of central importance to social and economic developments. Various innovation theories offer classifications to predict and assess their impact. This article reviews the usefulness of selected approaches and their application in the convergent communications sector. It focuses on the notion of disruption, the comparatively new distinction between disruptive and sustaining innovations, and examines how it is related to other innovation-theoretical typologies. According to the literature, there is a high frequency of disruptive changes in the field of internet protocol-based innovations in combination with wireless technology. A closer analysis reveals that these classifications and assessments not only differ in detail but are even contradictory. The article explains these differences by highlighting delicate choices that have to be taken by analysts applying the disruption concept. It argues that its applicability is comparatively low in the convergent communications sector and generalizations of single-firm assessments are hardly valid.